Comments on Papers by Ryce et al. on The Electrostatic Dispersion of Liquids

1974 ◽  
Vol 52 (11) ◽  
pp. 1046-1047
Author(s):  
V. E. Krohn
Keyword(s):  
Binary Fission ◽  
Electronic Charge ◽  
Daughter Droplets ◽  
Low Charge ◽  
Electrostatic Dispersion ◽  
Rayleigh Limit

It is noted that all drops carrying more than one unit of electronic charge (on their surface) are either metastable or unstable and that the energetically most favored mode of binary fission does not result in daughter droplets with charges exceeding the Rayleigh limit, although this limit would be closely approached by the smaller daughter droplet if this mode of fission were induced in drops of low charge relative to the Rayleigh limit. Also, it is suggested that the secondary fission observed by Ryce and Patriarche probably followed a primary fission which was highly asymmetric because of perturbations existing when the original drop was created.

The Ultrastructure of the Nuclear Events of Binary Fission in Paramecium bursaria and the Effects of Colchicine on Cell Division

1974 ◽  
Vol 32 ◽  
pp. 276-277
Author(s):  
L. M. Lewis
Keyword(s):  
Cell Division ◽  
Nuclear Envelope ◽  
Condensed Chromatin ◽  
Binary Fission ◽  
Paramecium Bursaria ◽  
Nuclear Events ◽  
Division Axis

The effects of colchicine on extranuclear microtubules associated with the macronucleus of Paramecium bursaria were studied to determine the possible role that these microtubules play in controlling the shape of the macronucleus. In the course of this study, the ultrastructure of the nuclear events of binary fission in control cells was also studied.During interphase in control cells, the micronucleus contains randomly distributed clumps of condensed chromatin and microtubular fragments. Throughout mitosis the nuclear envelope remains intact. During micronuclear prophase, cup-shaped microfilamentous structures appear that are filled with condensing chromatin. Microtubules are also present and are parallel to the division axis.

Relation Between Local Structure, Electric Dipole and Charge Carrier Dynamics in DHICA Melanin, a Model for Biocompatible Semiconductors

2019 ◽  
Author(s):  
Micaela Matta ◽  
Alessandro Pezzella ◽  
Alessandro Troisi
Keyword(s):  
Electronic Structure ◽  
Degrees Of Freedom ◽  
Structural Model ◽  
Computational Study ◽  
Oxidative Polymerization ◽  
Radical Scavenging ◽  
Charge Carriers ◽  
Electronic Charge ◽  
Polymer Semiconductors ◽  
Synthetic Pigments

<div><div><div><p>Eumelanins are a family of natural and synthetic pigments obtained by oxidative polymerization of their natural precursors: 5,6 dihydroxyindole and its 2-carboxy derivative (DHICA). The simultaneous presence of ionic and electronic charge carriers makes these pigments promising materials for applications in bioelectronics. In this computational study we build a structural model of DHICA melanin considering the interplay between its many degrees of freedom, then we examine the electronic structure of representative oligomers. We find that a non-vanishing dipole along the polymer chain sets this system apart from conventional polymer semiconductors, determining its electronic structure, reactivity toward oxidation and localization of the charge carriers. Our work sheds light on previously unnoticed features of DHICA melanin that not only fit well with its radical scavenging and photoprotective properties, but open new perspectives towards understanding and tuning charge transport in this class of materials.<br></p></div></div></div>

Field Effect Modulation of Electrocatalytic Hydrogen Evolution at Back-Gated Two-Dimensional MoS2 Electrodes

2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie
Keyword(s):  
Electric Field ◽  
Hydrogen Evolution ◽  
Active Sites ◽  
Density Functional ◽  
Electrode Materials ◽  
Density Functional Theory Calculations ◽  
Electronic Charge ◽  
Back Side ◽  
Gate Electrode ◽  
Conventional Manner

<div> <div> <div> <p> </p><div> <div> <div> <p>Electrocatalytic activity for hydrogen evolution at monolayer MoS2 electrodes can be enhanced by the application of an electric field normal to the electrode plane. The electric field is produced by a gate electrode lying underneath the MoS2 and separated from it by a dielectric. Application of a voltage to the back-side gate electrode while sweeping the MoS2 electrochemical potential in a conventional manner in 0.5 M H2SO4 results in up to a 140-mV reduction in overpotential for hydrogen evolution at current densities of 50 mA/cm2. Tafel analysis indicates that the exchange current density is correspondingly improved by a factor of 4 to 0.1 mA/cm2 as gate voltage is increased. Density functional theory calculations support a mechanism in which the higher hydrogen evolution activity is caused by gate-induced electronic charge on Mo metal centers adjacent the S vacancies (the active sites), leading to enhanced Mo-H bond strengths. Overall, our findings indicate that the back-gated working electrode architecture is a convenient and versatile platform for investigating the connection between tunable electronic charge at active sites and overpotential for electrocatalytic processes on ultrathin electrode materials.</p></div></div></div><br><p></p></div></div></div>

Additive-induced Miscibility Regulation and Hierarchical Morphology Enables 17.5% Binary Organic Solar Cells

2021 ◽  
Author(s):  
Jie Lv ◽  
Hua Tang ◽  
Jiaming Huang ◽  
Cenqi Yan ◽  
Kuan Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Organic Solar Cells ◽  
Organic Solar Cell ◽  
Power Conversion ◽  
Charge Trapping ◽  
Free Charge ◽  
Charge Generation ◽  
Low Charge ◽  
Hierarchical Morphology

Due to the barrierless free charge generation, low charge trapping, and high charge mobilities, the PM6:Y6 organic solar cell (OSC) achieves excellent power conversion efficiency (PCE) of 15.7%. However, the...

Effects of a scattering center on the ground-state energy of quantum-dot lithium

2017 ◽  
Vol 31 (07) ◽  
pp. 1750071
Author(s):  
Z. D. Vatansever ◽  
S. Sakiroglu ◽  
I. Sokmen
Keyword(s):  
Quantum Dot ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Electronic Charge ◽  
Strongly Correlated ◽  
Configuration Interaction Method ◽  
Charge Localization ◽  
Scattering Center ◽  
Spin Properties

In this paper, the effects of a repulsive scattering center on the ground-state energy and spin properties of a three-electron parabolic quantum dot are investigated theoretically by means of configuration interaction method. Phase transition from a weakly correlated regime to a strongly correlated regime is examined from several strengths and positions of Gaussian impurity. Numerical results reveal that the transition from spin-1/2 to spin-3/2 state depends strongly on the location of the impurity which accordingly states the controllability of the spin polarization. Moreover, broken circular symmetry results in more pronounced electronic charge localization.

scholarly journals The Consequences of Budding versus Binary Fission on Adaptation and Aging in Primitive Multicellularity

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 661
Author(s):  
Hanna Isaksson ◽  
Peter L. Conlin ◽  
Ben Kerr ◽  
William C. Ratcliff ◽  
Eric Libby
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Cellular Senescence ◽  
Carrying Capacity ◽  
The Other ◽  
Binary Fission ◽  
Fundamental Aspect ◽  
Accumulated Damage ◽  
Cell Age ◽  
Multicellular Organisms

Early multicellular organisms must gain adaptations to outcompete their unicellular ancestors, as well as other multicellular lineages. The tempo and mode of multicellular adaptation is influenced by many factors including the traits of individual cells. We consider how a fundamental aspect of cells, whether they reproduce via binary fission or budding, can affect the rate of adaptation in primitive multicellularity. We use mathematical models to study the spread of beneficial, growth rate mutations in unicellular populations and populations of multicellular filaments reproducing via binary fission or budding. Comparing populations once they reach carrying capacity, we find that the spread of mutations in multicellular budding populations is qualitatively distinct from the other populations and in general slower. Since budding and binary fission distribute age-accumulated damage differently, we consider the effects of cellular senescence. When growth rate decreases with cell age, we find that beneficial mutations can spread significantly faster in a multicellular budding population than its corresponding unicellular population or a population reproducing via binary fission. Our results demonstrate that basic aspects of the cell cycle can give rise to different rates of adaptation in multicellular organisms.

scholarly journals Identifying Ionic and Electronic Charge Transfer at Oxide Heterointerfaces

2020 ◽  
pp. 2004132
Author(s):  
Marc‐André Rose ◽  
Břetislav Šmíd ◽  
Mykhailo Vorokhta ◽  
Ivetta Slipukhina ◽  
Michael Andrä ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electronic Charge ◽  
Electronic Charge Transfer

Interfacial Energy Alignment at the ITO/Ultra-Thin Electron Selective Dielectric Layer Interface and Its Effect on the Efficiency of Bulk-Heterojunction Organic Solar Cells

2016 ◽  
Vol 16 (4) ◽  
pp. 3248-3253 ◽  
Author(s):  
Eiji Itoh ◽  
Yoshinori Goto ◽  
Yusuke Saka ◽  
Katsutoshi Fukuda
Keyword(s):  
Contact Resistance ◽  
Active Layer ◽  
Surface Potential ◽  
Organic Solar Cells ◽  
Indium Tin Oxide ◽  
Bulk Heterojunction ◽  
Electronic Charge ◽  
Photovoltaic Properties ◽  
Potential Measurement ◽  
Layer Interface

We have investigated the photovoltaic properties of an inverted bulk heterojunction (BHJ) cell in a device with an indium-tin-oxide (ITO)/electron selective layer (ESL)/P3HT:PCBM active layer/MoOx/Ag multilayered structure. The insertion of only single layer of poly(diallyl-dimethylammonium chloride) (PDDA) cationic polymer film (or poly(ethyleneimine) (PEI) polymeric interfacial dipole layer) and titanium oxide nanosheet (TN) films as an ESL effectively improved cell performance. Abnormal S-shaped curves were observed in the inverted BHJ cells owing to the contact resistance across the ITO/active layer interface and the ITO/PDDA/TN/active layer interface. The series resistance across the ITO/ESL interface in the inverted BHJ cell was successfully reduced using an interfacial layer with a positively charged surface potential with respect to ITO base electrode. The positive dipole in PEI and the electronic charge phenomena at the electrophoretic deposited TN (ED-TN) films on ITO contributed to the reduction of the contact resistance at the electrode interface. The surface potential measurement revealed that the energy alignment by the transfer of electronic charges from the ED-TN to the base electrodes. The insertion of the ESL with a large positive surface potential reduced the potential barrier for the electron injection at ITO/TN interface and it improved the photovoltaic properties of the inverted cell with an ITO/TN/active layer/MoOx/Ag structure.

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